Sound the retreat, coastal dwellers

Tom Horton

Sea level around the Chesapeake Bay is rising. Larger-than-ever storm surges are a certainty. Land is sinking further. The time has come to plan an orderly human retreat from more development along the watershed's low-lying edges.

The science that backs this advice gets drowned out when developers wave big money at county officials craving revenue. A classic "lose-lose" — for the environment and for taxpayers — results.

The most recent example comes from Virginia's Northumberland County Board of Supervisors. They have tentatively approved a massive home/resort/marina complex on Bluff Point, a marshy, wooded peninsula jutting into the Chesapeake from Virginia's lovely Northern Neck.

The rural county — four stoplights, 13,000 residents — acknowledges rising sea level in its master development plan, placing Bluff Point in a "conservation" zone, but after consulting experts paid for partly by developer Tom Dingledine of Charlottesville, Va., the supervisors granted an "exception."

The developer may put some houses on poles as high as eight feet in the air if needed; and that might seem reasonable, given sea level could rise about three feet in the next century, according to Virginia's Climate Change Commission. But this ignores that a foot of rise, with the Chesapeake's flattish edges, can move the bay inland as much as 180 feet, and you can't put roads and sewer lines on eight-foot poles.

Then there are storm surges. In 2006, Tropical Storm Ernesto caused surges along Virginia's bay shore of four to five feet — with six-to-eight-foot waves rolling atop that.

And while there's no proof the global warming that's driving sea levels up will cause more storms, it's a matter of physics that warmer water will fuel bigger ones.

Even without bigger storms, surges high enough to cause flooding at Bluff Point will occur three times a year by century's end — and that with just a two-foot rise in sea level.

Those predictions come from Northrop Grumman, contractor for the U.S. Navyin Newport News. The company is concerned about flooding while ships are being built, a process that can take six years for an aircraft carrier. With a three-foot sea-level rise, major floods would become 20 times as frequent.

The Bluff Point development is only one example of how our thinking about the bay's edges must adapt to the new reality of rising seas, says William A. "Skip" Stiles Jr., director of the Virginia nonprofit Wetlands Watch.

"If sea level is constant, your coastal region is your most valuable real estate; but with seas rising it becomes a money pit," he says.

Wetlands Watch regularly challenges places like Bluff Point on both ecological and fiscal grounds.

Tidal wetlands can stay ahead of sea-level rise up to a point by accumulating sediment and organic material and building on themselves. But projections are that tens of thousands of acres around the Chesapeake will drown in the next century. Dorchester County stands to lose around 85,000 acres of marsh and forest by 2100, according to Maryland climate change experts.

The only way many wetlands could adapt would be if adjacent uplands are left undeveloped, to give the wetlands a chance to migrate inland as the bay rises, Mr. Stiles says. That's a good reason to leave places like Bluff Point in conservation zones.

Wetlands Watch has also opposed some new wetlands created as part of Virginia's wetlands banking system, whereby developers get "credit" against wetlands they destroy. Mr. Stiles explains that many such "banked" wetlands are vulnerable to sea-level rise and will create no lasting environmental benefit. To date, Virginia has dismissed his challenges.

A double whammy for wetlands comes as rising waters and increasing erosion lead shoreline owners to armor their waterfront. This cuts off the sediment nearby wetlands need to build ahead of rising water, Mr. Stiles says.

Ultimately, the taxpayers will pick up the bills, bailing out places like Bluff Point as flooding escalates. Taxpayer-supported federal flood insurance programs, beach replenishment programs and the Federal Emergency Management Agency are all seeing costs soar as coastal flooding escalates. Private insurers have already pulled back from many coastal areas.

"It's time for all these government programs to recognize times have changed," Mr. Stiles says.

Indeed, while many bay scientists think a three-foot rise by 2100 is reasonable, they don't rule out a rise of up to six feet, based on the more rapid than expected melting of polar ice.

Hopes for reining in carbon dioxide and other climate change gases have dimmed with the recent refusal by the United States and China to take serious action before 2020 at the earliest. Already, we've heated the oceans to where they will keep releasing that heat for centuries, driving sea level higher no matter how sharply greenhouse gases are reduced.

It's time to sound the retreat.

Tom Horton, a former Baltimore Sun reporter, is the author of six books about the Chesapeake Bay. This article is distributed by Bay Journal News Service.